The Venusian biological reactor was a biological nanoscale tokamak originating on the planet Venus. The reactor was organic and consisted of numerous cell-like structures, each of which functioned as an independent nuclear reactor.

The reactor was absorbed by Dr. MacKenzie, one of the researchers on the project, in a freak accident. The cellular structures implanted themselves in her busom, which quickly began to grow substantially and burst forth from her shirt and undergarments. With her new "Venusian busom", she could directly channel and control the reactor's energy. With the powers granted her by the reactor, she crafted a new identity as the superheroine, "Ms. Venus".